Tool construction



P. R. CHIRCO TOOL CONSTRUCTION Jan. 9, 196s Filed July 9, 1964 NWN United States Patent O 3,362,211 TOOL CONSTRUCTION Peter R. Chrco, Utica, Mich., assignor to Huck Manufacturing Company, Detroit, Mich., a corporation of Michigan Filed July 9, 1964, Ser. No. 381,436 21 Claims. (Cl. 72-391) This invention relates to fluid actuated tools and more particularly to hydraulically actuated tools and to a hydraulic system for setting fasteners.

It is an object of the present invention to provide a compact, lightweight and relatively inexpensive hydraulically actuated tool for set-ting fasteners.

In the present invention a system for setting fasteners is provided utilizing a source of fluid pressure, an intensifier for increasing the output pressure from the source and a tool which is operative xfrom the pressure at the intensifier. With such a system a lightweight, compact, inexpensive tool can be utilized. It is therefore another object of this invention to provide a novel system for setting fasteners.

It is still another object to provide a novel hydraulic tool having a unique valve construction.

It is a general object of the present invention to provide a novel fluid actuated tool; it is another general object of this invention to provide a novel hydraulic system for setting fasteners.

Other objects, features, `and advantages of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is generally a schematic view of a preferred for-m -of the novel system of the present invention and includes .-a source of fluid pressure shown in block form, an intensier shown in a side elevational, sectional View, and a tool shown in an end view with some parts broken away;

FIGURE 2 is a sectional View to increased scale of the tool of FIGURE 1 taken substantially along the line 2 2; and

FIGURES 3 and 4 are sectional views of the tool of FIGURE 2 taken substantial-ly along the lines 3 3 and 4 4, respectively.

Looking now to FIGURE 1 a hydraulic system for setting fasteners is shown and includes a source of hydraulic pressure 10, a valve assembly 16, an intensifier 22, and a tool 24. The tool 24 is generally of the type for applying a relative axial force between two members and as specifically shown is adapted to set two piece fasteners of the type known as a lock bolt and as shown and described in United States patent to L. C. Huck, 2,531,049 issued Nov. 2l, 1950. The valve assembly 16 can be of a type well known in the art and is preferably of a type similar to the unit shown and described in the United States patent to Van Hecke, 3,001,548 issued Sept. 26, 1961 and hence is shown in box form.

The source of pressure 10 has a pressurized output line 12 and a low pressure return line 14. The source 10 can be of a type well known in the art and hence is generally shown in box form. The valve assembly 16 is connected to the lines 12 and 14 and in turn has a pair of lines 18 and 20 which can be selectively connected with one to the pressure line 12 and the other to the return line 14 or in just the reverse.

The intensifier 22 is generally comprised of an enclosed housing 26 having a reciprocable piston 2.8 located therein. The line 18 is connected to the intensifier 22 in communication with the head end of the housing 26. The piston 28 has a rod portion 30 which extends outwardly from the housing 26, hence reducing the piston area acting on the fluid at that end of the housing 26. Because of the difference in areas between the head and rod ends in housing 26 an increase of pressure is realized in the fluid at the rod end of the housing 26 in response to lluid pressure applied at the head end near the line 18. A line 32 is connected to the intensier 22 in communication with the rod end of the housing 26. The line 32 from intensifier 22 and the line 20 from the valve assembly 16 are connected to the tool 24 for its actuation in a manner to be presently seen.

The tool 24 in general comprises a cylinder section 33 and a nose section 34. The cylinder section 33 includes a cylindrical body portion 36 having a cap assembly 38 at its rearward end and a cylindrical adaptor 40 at its forward end. The cap assembly 38 includes an annular plug portion 42 which is held against a shoulder 44 at the rearward end of cylindrical portion 36 by means of a retaining ring 46. A seal is provided between the mating surfaces of plug portion 42 and ofthe cylindrical body portion 36 by means of seal 48 supported in a groove in the plug portion 42. An annular end portion S0 is coaxially fixed to the rearward end of the plug portion 42, by means of a plurality of bolts 51. The plug portion 42 and end portion S0 together define a central through opening S2 which serves a purpose to be described.

The adaptor 40 is secured against a shoulder 54 at the forward end of the cylindrical body portion 36 by means of a retaining ring 56 in a groove in the adaptor 40 and extends from the cylinder section 33 forwardly into the nose section 34. A radial seal 57 located in a groove in the adaptor 40 provides a seal between the radial surface of the bore 59 at the shoulder 54 and the adaptor 40. A tubular anvil member 58 is secured to the forward end of the adaptor 40. The anvil member 58 and adaptor 40 have telescoping mating end portions and have 4annular ring portions 62 and 64, respectively, in juxtaposition with each other. An annular, generally U-sectional two-piece ring member 66 overengages both ring portions 62 and 64 to axially Secure the anvil member 58 and adaptor 40 together. The two pieces of the ring member 66 are in turn radially held together by a one-piece, annular cup-shaped retainer 68 which overengages the ring member `66. A retainer ring 70 in a groove in theanvil member `58 axially retains the retainer 68.

The forward end of the anvil member 58 terminates in an anvil portion 72 which has a reduced diameter, flared aperture 74 which is formed in accordance with means known in the art to swage fasteners of the type shown in the Huck patent (supra).

A piston 76 has a head portion 78 located within the cylindrical body portion 36 and is reciprocable in response to fluid presure between the plug portion 42 and the adaptor 40. The piston 76 has a rod portion 80 extending forwardly through a bore 82 in the cylindrical adaptor 40. An annular seal 84 islocated in a groove in the radial surface of the bore 82 and provides a seal with the rod portion 80. An annular piston ring seal 86 is located in a groove in the head portion 78 and provides a seal with the internal surface of the body portion 36.

The piston 76 has a central through bore 88 which is in coaxial alignment with the through bore 52 in the cap assembly 38. A tubular sleeve 90 has one end fixed within the forward end of bore 52 against a shoulder 92 via a retaining ring 94 and extends coaxially and matably into the through bore 88. An annular seal 96 is located in a groove on the surface of bore 52 and seals the rear end of the sleeve 90 while an annular seal 98 located in a groove in the surface of bore 88 seals the forward end of the sleeve 90. Thus it can be seen that the plug portion 42 of cap assembly 38 and the adaptor 40 is in cooperation with the body portion 36 and that the piston 76 and plug portion 42 are in cooperation with the sleeve 90 and define a totally enclosed chamber or cylinder 100.

A plurality of passages define a single fluid passageway 102 from the outer surface of the end portion 50 through the plug portion 42 and in communication with the head end of the cylinder 100. The opposite end of line from the valve assembly 16 is connected to the outer end of the passageway 102. A plurality of passages define a single fluid passageway 104 from the outer surface of the end portion 50 through the plug portion 42 and into the cylinder 100; as will be seen the passageway 104 does not open into the head end of the cylinder 100. The opposite end of line 32 from the rod end of the intensifier 22 is connected to the outer end of the passageway 104.

The inner end of the passageway 104 is connected to a double acting valve assembly 106 which includes a tubular member 108 having a central aperture 110. The tubular member 108 has one end located in a counterbore 112 at the inner end of the passageway 104 with the aperture 110 in communication therewith. An annular seal 114 located in a groove in the counterbore 112 provides a seal with the tubular member 108 thereby assuring that the fluid must travel between the aperture 110 and the passageway 104. The tubular member 108 extends through the cylinder 100 from the counterbore 112 in plug portion 42 into a counterbore 116 in the rearward facing surface 118 of the adaptor 40. The tubular member 108 passes through an axially offset bore 120l which extends through the head portion 78 of piston 76. The tubular member 108 has a transverse bore or port 119 in communication with aperture 110 and located at its forward end proximate the surface 118 of the adaptor 40. The head portion 78 has a radially extending slot 123 which communicates with the bore 120 and is in line with the port 119. A similar radially extending slot 125 in the surface 118 of adaptor 40 is in confrontation with slot 123 and, with the piston 76 in its forwardmost position (as shown in FIGURE 2), defines therewith a fluid path 127 in communication with the port 119. Again with the piston 76 in its forwardmost position, a pair of confronting annular grooves in head portion 78 and surface 118 define an annular fluid passage 129 which communicates with radial passage 127. The passage 129, as will be seen, permits fluid pressure to be applied to the rod end of the cylinder 100, with the piston 78 in its forwardmost position and, hence, aids in the initiation of rearward movement of piston 76 in response to pressure at the rod end. Thus two fluid paths are defined for communication with the cylinder 100. A first fluid path is defined by passageway 102 through cap assembly 38 and communicates with the head end of the cylinder 100. A second fluid path is defined by the passageway 104 through cap assembly 38, the aperture 110 and port 119, both in tubular member 108, and communicates with the rod end of the cylinder 100'. It is often desirable with fluid actuated devices to be able to automatically reduce the actuating pressure in the cylinder when the piston reaches the end of its stroke. Such pressure relief prevents the buildup of extreme pressure which could result in damage to seals, components, etc. The valve assembly 106, in a manner to be presently seen, automatically provides such pressure relief at the end of the stroke of piston 76 in both its rearwardmost and forwardmost positions.

Looking now to FIGURES 3 and 4, the outer surface of the tubular member generally has a circular crosssection which is substantially of the diameter of the bore 120 in head portion 78 and permits the piston 76 to reciprocate relatively thereto without interference. However the forward and rearward portions of the tubular member 108 are provided with flats, such as flats in FIGURE 3, such that with the bore 120 of head portion 78 located completely in alignment with either of these end portions then passages, such as passages 124, are defined which communicate the rod end with the head end of the cylinder 100. An intermediate portion 126 of the tubular member 108 is maintained with the full circular cross section such that, when any portion of the bore 120 is in radial alignment therewith, the rod and head ends of the cylinder are substantially no longer in fluid communication. The intermediate portion 126 is provided to be of an axial length such that the passage 124 is opened to communicate the rod and head ends of the cylinder 100 just prior to the completion of movement of the piston 76 to either its forwardmost or rearwardmost positions. Thus the valve assembly 106 is automatically operative to relieve fluid pressure at the ends of the stroke of the piston 76 to thereby protect the tool from damage as mentioned before. With the combination thus far shown and described, however, the valve assembly 106 serves another useful function which will be apparent from the description which follows.

The tool 24, as previously described, being specifically adaptable to set fasteners of the type described in the patents to Huck, supra, has its power stroke as the piston 76 is moved rearwardly in the cylinder 100. To actuate the tool 24 for its power stroke the valve assembly 16 is placed in a condition by the operator in which the pressure line 12 from the source of fluid pressure 10 is connected to line 18 and the return line 14 is connected to line 20. Actuation of valve assembly 16 can be by means similar to that used for actuation of the unit shown in the patent to Van Hecke, supra. Fluid under pressure then is transmitted to the head side of the intensifier 22 and fluid at increased pressure at the rod end is caused to flow out through the line 32. This intensified fluid pressure is applied to the rod end of the cylinder 100 via the passageway 104, aperture and port 119; the passage 127 and passage 129 aid in the initial application of fluid pressure in the manner previously described. Initially with the piston 76 at its forwardmost position some of the fluid applied at the rod end of the cylinder 100 is transmitted to the head end of the cylinder 100 in the passage 124, thereby resulting in a pressure drop at the rod end. As the piston 76 is moved rearwardly a short distance the bore moves into alignment with the intermediate portion 126 hence closing the passages 124 and resulting in an increase in pressure at the rod end and hence an increase in the force on the piston 76. This increased pressure continues for substantially the remainder of the power stroke of the piston 76 until the piston 76 has reached a position proximate its rearwardmost position at which the intermediate portion 126 no longer is located within or in radial alignment with the bore 120. At this position the passages, similar to passage 124, are opened permitting fluid to flow from the rod to the head end of cylinder 100 thereby reducing the pressure at the rod end. Thus if at the end of the power stroke of piston 76, the operator maintains the valve assembly 16 in the position to drive the piston 76 rearwardly excessive pressure will not be built up in the cylinder 100 as a result of the operation of the double acting valve assembly 106. Note that as the piston 76 moves rearwardly the fluid at the head end of cylinder 100 is ejected through passageway 102, line 20, and to the return line 14 via the valve assembly 16. In order to facilitate the application of fluid pressure as well as the ejection of fluid from the head end of the cylinder 100 the plug portion 42 is provided with an axially forwardly extending, centrally located, boss portion 130 which engages the central portion of the head portion 78 leaving a substantial clearance between the remaining, confronting surface 0f the head portion 78 and plug portion 42.

In order to return the piston 76 to its forwardmost position the operator places the valve assembly 16 in the alternate condition with the pressure line 12 connected to the line 20 and with the return line 14 connected to the line 18. Thus fluid pressure is applied to the head end of the cylinder 100 via the line 20 and passageway 102 causing the piston 76 to move forwardly. The fluid in the rod end is ejected through the port 119, the aperture 110, the passageway 104, the line 32 and into the rod end ofthe intensifier 22. This return fluid causes the piston 28 to move back toward the head end of the housing 26 causing fluid to be ejected back into the source via the fluid line 18, valve assembly 16 and line 14. Again, when the piston 76 of tool 24 reaches its forwardmost position the passages 124 are opened permitting fluid to flow from the head to the rod end of cylinder 100. This additional return fluid from the source 10 to the rod end ofthe intensifier 22 will act as makeup and assure that the piston 28 will always be returned proximate to its extreme starting position and hence prevent stalling of the intensifier 22, i.e., the piston 28 on the work stroke starting at an intermediate position such that it reaches the end of its stroke and hence can no longer supply the cylinder 100 before the drive piston 76 reaches the end of its stroke. Note that on the return stroke the lower pressure from the source 10 rather than the increased pressure from the intensifier 22 is applied to the tool 24. The valve assembly 16 in accordance with the patent to Van Hecke, supra, could be provided with additional means for automatically reducing the pressure if it exceeds a preselected maximum on the return stroke to further protect the tool 24 as well as means for automatically relieving excessive pressure from the source 10 on the power stroke to thereby protect the intensifier 22, i.e., on the power stroke the pressure fluid is applied to intensifier 22.

As previously noted, the tool 24 as specifically shown is used to set fasteners of the type shown in the patent t0 Huck, supra, Thus the forward end of the rod portion 80 of piston 76 is threadably connected to the rearward end of a tubular collet member 130 which is matably, slidably located within the anvil member 58. The collet member 130 has a central, through aperture with a radially inwardly inclined, axially outwardly extending frusto conical surface portion 132 near its forward end. The surface portion 132 tapers into a reduced diameter opening 134 at the forward end of the collet 130. A plurality of gripping or chuck jaws 136 are located within the collet member 130 and have outer surfaces which mate with the surface portion 132. The closing of the chuck jaws 136 is controlled by a follower assembly 138. The following assembly 138 includes a tubular sleeve 140 which is stopped at the rearward end of the collet member 130 by means of a retainer ring 142. A spring member 144 is located about the sleeve 140 and has one end in engagement with a shoulder 148. The opposite end of spring member 144 engages a shim 146 located at one end of a tubular follower member 150 and urges the latter axially forwardly. The following member 150 in turn engages a tubular cap member 152 via an O-ring 154 located therebetween with the cap member 152 engaging the rearward surfaces of the chuck jaws 136. The mating surfaces between the cap member 152 and chuck jaws 136 are contoured such that the jaws 136 are urged radially outwardly into engagement with the surface portion 132 of the collet member 130 as a result of the continuous axially forwardly directed force applied by the follower assembly 138. Thus in FIGURE 2 the chuck jaws 136 are urged toward their closed position but are held open by a tubular, chuck jaw release member 156 which is slidably supported within the reduced diameter bore 134 at the forward end of the collet member 130. A flange member and retaining ring assembly 158 is located in a groove intermediate the ends of the release member 156 and is engageable with the forwardmost surface of the collet member 130 to limit the axially inward movement of the release member 156. A shoulder 160 on the rearward end of the release member 156 is engageable with a shoulder 162 in the bore 134 and limits the axially outward movement of release member 156. The release member 156 serves a purpose to be presently understood.

In operation as the piston 76 moves rearwardly, the collet member 130 moves rearwardly while the follower assembly `138 causes the chuck jaws 136 and release mem'ber 156 to move forwardly. The relative forward motion of chuck jaws 136 causes them to be moved radially inwardly along the surface portion 132 to a locked or closed position at which the pin of a fastener to be set (see Huck patent, supra) is gripped. Further rearward movement of piston 76 causes the flared aperture 74 of the anvil portion 72 to move over and swage a collar onto the pin. Further axially rearward movement of piston 76 causes the pin to break at a reduced diameter portion. At this time the operator causes piston 76 to move forwardly. The release member 156 engages the swaged collar and initially causes the chuck jaws to open to release the severed portion of the pin. As the piston 76 moves to its forwardmost position, the release member 156 drives the swaged collar out of the aperture 74 thus releasing the tool 24 for setting the next fastener. Note that the cylinder section 33 and nose section 34 define a continuous opening 164 completely through the tool 24 thereby permitting the ejection of broken pin portions or pin tails out the rearward end of the tool 24.

The valve assembly 106 in addition to the other advantages mentioned also permits the assembly of all of the necessary fluid lines at the rear of tool 24 and through the cap assembly 38. In conventional constructions one of the fluid lines would have to be connected through the cylinder body portion 36, hence complicating its construction.

While it will be apparent that the preferred embodiment of the invention disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. A fluid actuated device for actuation by a source of fluid pressure comprising a cylinder having an enclosed cavity, a piston mounted in said cavity for reciprocation between opposite ends of said cylinder in response to the application of fluid pressure to opposite sides of said piston, first fluid passage means at one end of said cylinder and fluid communicating said one end of said cylinder with the source, second' fluid passage means separate from said cavity and extending from Said one end to the opposite end through said cavity and fluid communicating said opposite end of said cylinder with the source, said second fluid passage means being fixed relative to said piston.

2. A fluid actuated device for actuation by a source of fluid pressure comprising a cylinder having an enclosed cavity, a piston mounted in said cavity for reciprocation between opposite ends of said cylinder in response to the application of fluid pressure to opposite sides of said piston, first fluid passage means at one end of said cylinder and fluid communicating said one end of said cylinder with the source, second fluid passage means separate from said cavity extending from said one end to the opposite end through said cavity and fluid communicating said opposite end of said cylinder with the source said second fluid passage means being fixed relative to said piston, valve means for fluid communicating together said cylinder on said opposite sides of said piston with said piston located at one of said ends of said cylinder.

3. A fluid actuated device for actuation by a source of fluid pressure comprising a cylinder having an enclosed cavity, a piston mounted in said cavity for reciprocation between opposite ends of said cylinder in response to the application of fluid pressure to opposite sides of said piston, first fluid passage means at one end of said cylinder and fluid communicating said one end of said cylinder with the source, second fluid passage means separate from said cavity and extending from said one end to the opposite end through said cavity and fluid communicating said opposite end of said cylinder with the source, said second fluid passage means fbeing fixed relative to said piston, valve means for fluid communicating together said cylinder on said opposite sides of said piston with said piston located at either of said ends of said cylinder.

4. A fluid actuated device for actuation by a source of fluid pressure comprising a cylinder having an enclosed cavity, a piston mounted in said cavity for reciprocation between opposite ends of said cylinder in response to the application of fluid pressure to opposite sides of said piston, first fluid passage means at one end of said cylinder and fluid communicating said one end of said ycylinder with the source, second fluid passage means separate from said cavity and extending from said one end to the opposite end through said cavity and through said piston and fluid communicating said opposite end of said cylinder with the source, said second fluid passage means being fixed relative to said piston.

5. A fluid actuated device for actuation by a source of fluid pressure comprising a cylinder having an enclosed cavity, a piston mounted in said cavity for reciprocation between opposite ends of said cylinder in response to the application of fluid pressure to opposite sides of said piston, first fluid passage means at one end of said cylinder and fluid communicating said one end of said cylinder with the source, means defining a second fluid passage means separate from said cavity and extending from said one end to the opposite end through said cavity and through an opening through said piston and fluid communicating said opposite end of said cylinder with the source and defining valve means operative with said opening through said piston for fluid communicating together said cylinder on said opposite sides of said piston with said piston located at one of said ends of said cylinder.

6. A fluid actuated device for actuation yby a source of fluid pressure comprising a cylinder having an enclosed cavity defined by a cylindrical body portion and opposite end portions, a piston mounted in said cavity for reciprocation between said opposite end portions of said cylinder in response to the application of fluid pressure to opposite sides of said piston, first fluid passage means fluid communicating said one end of said cylinder with the source through one of said end portions, second fluid passage means separate from said cavity and extending through said one of said end portions through said cavity and fluid communicating the opposite end of said'cylinder with the source, said second fluid passage means being fixed relative to said piston.

7. A fluid actuated device for actuation by a source of fluid pressure comprising a cylinder having an enclosed cavity defined by a cylindrical body portion and opposite end portions, a piston mounted in said cavity for reciprocation between said opposite end portions of said cylinder in response to the application of fluid pressure to opposite sides of said piston, first fluid passage means fluid communicating said one end of said cylinder with the source through one of said end portions, second fluid passage means separate from said cavity and extending through said one of said end portions through said cavity and fluid communicating the opposite end of said cylinder with the source, said second passage means comprising a tubular member fixed Irelative to said piston and extending between said end portions and having an inlet at said one of said end portions in fluid communication with a passageway through said one of said end portions and an outlet proximate the other of said end portions and in fluid communication with said opposite end of said cylinder, and fluid passage means including said tubular member for providing pressure relief at least at one end of the path of travel of said piston in said cavity.

8. A fluid actuated device for actuation by a source of fluid pressure comprising a cylinder having an enclosed cavity defined by a cylindrical body portion and opposite end portions, a piston mounted in said cavity for reciprocation between said opposite end portions of said cylinder in response to the application of fluid pressure to opposite sides of said piston, an aperture extending axially through said piston, first fluid passage means fluid communicating said one end of said cylinder with the source through one of said end portions, second fluid passage means separate from said cavity and extending through said one of said end portions through said cavity and fluid communicating the opposite end of said cylinder with the source, said second passage means comprising a tubular member fixed relative to said piston and extending between said end portion and through said aperture in sai-d piston and having an inlet at said one of said end portions in fluid comiiiunication with a passageway through said one of said end portions and an outlet proximate the other of said end portions and in fluid communication with said opposite end of said cylinder, and fluid passage means including said tubular member for providing pressure relief at least at one end of the path of travel of said piston in said cavity.

9. A fluid actuated device for actuation by a source of fluid pressure comprising a cylinder having an enclosed cavity defined by a cylindrical body portion and opposite end portions, a piston mounted in said cavity for reciprocation between said opposite end portions of said cylinder in response to the application of fluid pressure to opposite sides of said piston, an aperture extending axially through said piston, first fluid passage means fluid communicating said one end of said cylinder with the source through one of said end portions, second fluid passage means extending through said one of said end portions through said cavity and fluid communicating the opposite end of said cylinder with the source, said second passage means comprising a tubular member extending between said end portions and through said aperture in said piston and having an inlet at said one of said end portions in fluid communication with a passageway through said one of said end portions and an outlet proximate the other of said end portions and in fluid communication with said opposite end of said cylinder, said tubular member having an intermediate portion having an outer contour similar to the contour of said aperture of said piston substantially blocking fluid flow through said aperture from said opposite sides of said piston when said intermediate portion and said aperture are radially aligned, said tubular member having at one end an end segment of a contour dissimilar to the contour of said aperture of said piston for defining a passageway communicating said opposite sides of said piston when lsaid end segment and said aperture are radially aligned.

10. A fluid actuated device for actuation by a source of fluid pressure comprising a cylinder having an enclosed cavity defined by a cylindrical body portion and opposite en-d portions, a piston mounted in said cavity for reciprocation between said opposite end portions of said cylinder in response to the application of fluid pressure to opposite sides of said piston, an aperture extending axially through said piston, first fluid passage means fluid communicating said one end of said cylinder with the source through one of said end portions, second fluid passage means extending through said one of said end portions through said cavity and fluid communicating the opposite end of said cylinder with the source, said second passage means comprising a tubular member extending between said end portions and through said aperture in said piston and having an inlet at said one of said end portions in fluid communication with a passageway through said one of said end portions and an outlet proximate the other of said end portions and in .fluid communication with said opposite end of said cylinder, said tubular member having an intermediate portion having an outer contour similar to the contour of said aperture of -said piston substantially blocking fluid flow through said aperture from said opposite sides of said piston when said intermediate portion and said aperture are radially aligned, said tubular member having at one end an end segment of a contour dissimilar to the contour of said aperture of said piston for defining a passageway communicating said opposite sides of said piston when said end segment and said aperture are radially aligned, said aperture and the outer contours of said intermediate portion and said one segment having similar circular crosssections with at least one fiat formed along said end segment.

11. The apparatus of claim with said tubular member having an opposite segment similar to said end segment formed at the other end.

.12. A fluid actuated device for actuation by a source of fluid pressure comprising a cylinder having an enclosed cavlty, a piston mounted in said cavity for reciprocation between opposite ends of said cylinder in response to the application of fluid pressure to opposite sides of said piston, said piston having a rod portion extending axially forwardly and outwardly from one end of said cylinder, gripping means connected to the forward end of said rod portion and actuable responsively to axial movement of said piston for gripping a fastener to be set, anvil means connected to said cylinder for reacting the axial force applied to the fastener via said gripping means, first fluid passage means at yone end of said cylinder and fiuid communicating said one end of said cylinder with the source, second fluid passage means for providing pressure relief only at at least one extreme end of the path of travel of said piston in said cavity and extending from said one end through said cavity and fluid communicating the opposite ends of said cavity on said opposite sides of said piston, said second fiuid passage means including an axially extending rod member fixed relative to said piston.

13. A fluid actuated device for actuation by a source of fiuid pressure comprising a cylinder having an enclosed cavity defined by a cylindrical body portion and opposite end portions, a piston mounted in said cavity for reciprocation between said opposite end portions of said cylinder in response to the application of fluid pressure to opposite sides of said piston, an aperture extending axially through said pist-on, first fluid passage means fluid communicating said one endvof said cylinder with the source through one of said end portions, second fiuid passage means extending through said one of said end portions through said cavity and fluid communicating the opposite end of said cylinder with the source, said second passage means comprising a tubular member extending between said end portions and through said aperture in said piston and having an inlet at said one of said end portions in fiuid communication with a passageway through said one of said end portions and an outlet proximate the other of said end portions and in fluid communication with said opposite end of said cylinder, said tubular member having an intermediate portion having an outer contour similar to the contour of said aperture of said piston substantially blocking fiuid flow through said aperture from said opposite sides of said piston when said intermediate portion and said aperture are radially aligned, said tubular member having at one end an end segment of a contour dissimilar to the contour of said aperture of said piston for defining a passageway communicating said opposite sides of said piston when said end segment and said aperture are radially aligned, said piston having a rod portion extending axially forwardly and -outwardly from one end of said cylinder, gripping means connected to the forward end of said rod portion and actuable responsively to axial movement of said piston for gripping a fastener to be set, anvil means connected to said cylinder for reacting the axial force applied to the fastener via said gripping means.

14. In a system actuable by a source of fluid pressure having an inlet and an outlet, the combination comprising a first cylinder, a first piston mounted in said first cylinder for reciprocation, said first piston having head and rod portions whereby fiuid pressure applied to the head side of said cylinder results in an increased pressure at the rod side, a second cylinder remote from said first cylinder, a second piston mounted in said second cylinder for reciprocation, said second piston having head and rod sections with said rod section extending axially forwardly and outwardly from one end of said second cylinder, gripping means connected to the forward end of said rod section and actuable responsively to axial movement of said second piston for gripping a fastener to be set, anvil means connected to said second cylinder for reacting the axial force applied to the fastener via said gripping means, valve means for fluid communicating together said second cylinder on opposite sides of said section piston with said second piston located at either end only of said second cylinder, said valve means including an axially extending rod member fixed relative to said second piston, first fiuid passage means fluid communicating the rod ends of said first and second cylinders, second fluid passage means in fluid communication with the head end of said first cylinder, third fluid passage means in fiuid communication with the head end of said second cylinder, and means selectively connecting each of said second and third fiuid passage means to one of the inlet and outlet of the source.

15. In a system actuable by a source of fluid pressure having an inlet and an outlet, the combination comprising a first cylinder, a first piston mounted in said first cylinder for reciprocation, said first piston having head and rod portions whereby fiuid pressure applied to the head side of said cylinder results in an increased pressure at the rod side, a second cylinder remote from said first cylinder, a second piston mounted in said second cylinder for reciprocation, said second piston having head and rod sections with said rod section extending axially forwardly and outwardly from one end of said second cylinder, gripping means connected to the forward end of said rod section and actuable responsively to axial movement of said second piston for gripping a fastener to be set, anvil means connected to said second cylinder for reacting the axial force applied to the fastener via said gripping means, valve means for fiuid communicating together said second cylinder on opposite sides of said second piston with said second piston located at either end of said second cylinder, first fluid passage means fluid cOmmunicating the rod ends of said first and second cylinders, second uid passage means in fluid communication with the head end of said first cylinder, third fluid passage means in fiuid communication with the head end of said second cylinder, and means selectively connecting each of said second and third fluid passage means to one of the inlet and outlet of the source, said valve means comprising a fixed member located Within said second cylinder and fixed relative to said second piston and extending through an aperture through said second piston, said fixed member having end portions and an intermediate portion located therebetween, said intermediate portion having an outer contour similar to the contour of said aperture of said second piston and substantially blocking fluid flow through said aperture when said intermediate portion and said aperture are radially aligned, each of said end portions of said tubular member having a contour dissimilar to the contour of said aperture of said second piston for defining a passageway communicating opposite sides of said second piston when said aperture and said each of said end portions are radially aligned.

16. The apparatus of claim 15 with said rst fiuid passage means including an aperture extending axially into said fixed member with an outlet in communication with said second cylinder at the rod end of said second cylinder.

17. A fiuid actuated device for actuation by a source of fluid pressure comprising a cylinder having an enclosed cavity defined by a cylindrical body portion and opposite end portions, a piston mounted in said cavity for reciprocation between said opposite end portions of said cylinder in response to the application of fiuid pressure to opposite sides of said piston, an aperture extending axially through said piston, first fluid passage means fluid communicating one of the ends of said cylinder with the source, second fluid passage means extending through said cavity and fluid communicating the opposite end of said cylinder with the source, said second passage means comprising a tubular member extending between said end portions and through said aperture in said piston and having an inlet at one end and means for fluid connecting said one end to the source and having an outlet proximate the other of said end portions and in uid communication with Said opposite end of said cylinder, said tubular member having an intermediate portion having an outer con# tour similar to the contour of said aperture of said piston substantially blocking ud flow through said aperture from said opposite sides of said piston when said intermediate portion and said aperture are radially aligned, said tubular member having at one of its ends an end segment of a contour dissimilar to the contour of said aperture of said piston for defining a passageway communicating said opposite sides of said piston when said end segment and said aperture are radially aligned.

18. A uid actuated device for driving fasteners or the like comprising a cylinder having an enclosed cavity, a piston mounted in said cavity for reciprocation between opposite ends of said cavity in response to the application of iiuid pressure to opposite sides of said piston, first and second fluid passageways leading to respectively opposite ends of said cavity for communicating said opposite ends of said cavity with a source of fluid pressure, third fluid passage means for providing pressure relief only at at least one extreme end of the path of travel of said piston in said cavity and extending through said cavity for Huid communicating said opposite ends of said cavity, said third tiuid passage means comprising an axially extending rod member fixed in said cavity relative to said piston and having an axially extending surface defining with said piston a iirst fluid passage providing uid communcation between said opposite ends ofthe cavity.

19. The device of claim 18 with said axially extending member having an axially extendingintermediate portion cooperating with said piston to block uid iiow between the opposite ends of said cavity when said piston is intermediate said opposite ends of said cavity.

20. The device of claim 19 with said axially extending member extending between said opposite ends of said cavity and passing through a bore in said piston with said axially extending surface and said bore defining said rst iiuid passage.

21. The device of claim 20 with said axially extending member being tubular and defining a second uid passage for communicating uid through said cavity to the one end of said cavity through said cavity.

References Cited UNITED STATES PATENTS 1,002,027 8/1911 Brown 92-110 2,068,102 1/1937 Gaines 91-401 2,088,859 8/1937 Huck 72-391 2,415,181 2/1947 Johnson 92-110 3,042,244 7/1962 Van Hecke 72-391 3,082,898 3/1963 Bosch 72--391 3,182,563 5/1965 Neilan 91-401 3,254,522 6/1966 Elliott 72-391 CHARLES W. LANHAM, Primary Examiner.

G. P. CROSBY, Assistant Examine/ UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 3,362,211 January 9, 1968 Peter R. Chrco It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below Column 3, line 67, for "as flats in" read as flats 122 in column 10, line 5, for "section" read second Signed and sealed this 8th day of April 1969.

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, J r.

Commissioner of Patents Attesting Officer 

1. A FLUID ACTUATED DEVICE FOR ACTUATION BY A SOURCE OF FLUID PRESSURE COMPRISING A CYLINDER HAVING AN ENCLOSED CAVITY, A PISTON MOUNTED IN SAID CAVITY FOR RECIPROCATING BETWEEN OPPOSITE ENDS OF SAID CYLINDER IN RESPONSE TO THE APPLICATION OF FLUID PRESSURE TO OPPOSITE SIDES OF SAID PISTON, FIRST PASSAGE MEANS AT ONE END OF SAID CYLINDER AND FLUID COMMUNICATING SAID ONE END OF SAID CYLINDER WITH THE SOURCE, SECOND FLUID PASSAGE MEANS SEPARATE FROM SAID CAVITY AND EXTENDING FROM SAID ONE END TO THE OPPOSITE END THROUGH SAID CAVITY AND FLUID COMMUNICATING SAID OPPOSITE END OF SAID CYLINDER WITH THE SOURCE, SAID SECOND FLUID PASSAGE MEANS BEING FIXED RELATIVE TO SAID PISTON. 